Gravity Affects All Matter in the Universe

Two planets have a certain gravitational force between them. What would happen if the distance between the two planets suddenly decreased?

• The gravitational force between the two planets would decrease.

• The mass of the planets would decrease.

• The gravitational force between the two planets would remain constant.

• The gravitational force between the two planets would increase.

Each of the pairs of objects listed are the same distance apart. Which pair of objects has the smallest gravitational force?

• elephant and mouse

• book and pen

• car and bicycle

• There is no gravitational force between any of these pairs of objects.

What would be the force between a satellite and Earth if the mass of the Earth was halved?

• The force would be the same as it is now.

• The force would be twice what it is now.

• The force would be one-half what it is now.

• The force would be one-fourth what it is now.

Why does an apple fall from the tree to the ground instead of floating in the air?

• The apple does not experience any gravitational force because it is not a planet.

• The gravitational force between the tree and the apple is so strong that it pushes the apple down.

• There is no gravitational force between the tree and the apple, so Earth's gravitational force pulls the apple down.

• There is a gravitational force between the tree and the apple, but Earth's gravity is stronger, so Earth's gravity pulls the apple down.

What characteristic of a black hole contributes to its immense gravitational pull?

• It has a very small size and a mass much larger than the sun.

• It has a very large size and a mass much smaller than the sun.

• It has a very small size and a mass much smaller than the sun.

• It has a very large size and a mass much larger than the sun.

Isaac Newton developed the law of universal gravitation. State the law of universal gravitation in words.

How does the gravitational pull of the sun affect the velocity of a planet in its orbit?

• It causes a continuous acceleration of the planet.

• It causes a continuous deceleration of the planet.

• It causes the planet's velocity to remain constant throughout its orbit.

• It causes the planet's velocity to increase and decrease throughout its orbit.

Explain how gravity played a role in the creation of the solar system and the planets' orbits around the sun.

How does the gravitational pull of the moon affect the tides on Earth?

• It causes the tides to rise and fall.

• It has no effect on the tides.

• It causes the tides to remain constant.

• It causes the tides to rise only.